JP5125032B2 - Electric position adjustment type steering device - Google Patents

Description

  The present invention relates to an electric position adjustment type steering apparatus configured to be position-adjustable by an electric actuator.

Conventionally, in an electric position adjustment type steering apparatus equipped with at least one of an electric tilt mechanism and an electric telescopic mechanism, in order to eliminate backlash at the meshing portion between the worm wheel and the male thread portion of the adjustment rod, There is known an electric position adjustment device that is composed of a metal main body and a synthetic resin auxiliary body, and is configured to be screwed in while expanding the male screw portion of the adjustment rod into the auxiliary screw hole of the auxiliary body (for example, , See Patent Document 1).
Japanese Utility Model Publication No. 7-11481 (first page, FIG. 1 and FIG. 2)

  However, in the conventional example described in Patent Document 1, a screw hole is provided at the center of the worm wheel, so that the worm wheel meshing with the worm also functions as a nut that engages with the male screw of the connecting rod. Therefore, although the number of parts can be reduced, if the worm wheel is made of metal and the worm meshing with the worm wheel is made of metal, the operating noise due to the friction between the two becomes large, and this operating noise is reduced. However, it is necessary to use a high-cost alignment bearing as a bearing for supporting the worm wheel, and there is an unsolved problem that the whole manufacturing cost increases.

  In order to solve this unsolved problem, for example, as shown in FIG. 11, the entire worm wheel 2 meshing with the worm 1 is made of a synthetic resin material, and a large-diameter portion 2a at the center portion and small-diameter portions 2b at both ends thereof. 2c, the helical gear 3 is formed on the outer peripheral surface of the large-diameter portion 2a, the female screw 4 is formed on the inner peripheral surface, and both ends of the worm wheel 2 can be freely rotated by ball bearings 5 and 6. It can be considered that the male screw 8 of the connecting rod 7 is screwed to the female screw 4 while being supported.

  Thus, when the entire worm wheel 2 is formed of a synthetic resin material, since the tooth base of the helical gear 3 formed on the large diameter portion 2a abuts on the inner rings of the ball bearings 5 and 6, for example, in FIG. When an impact load F is applied to the rod 7 from the right side, the impact load F is received at the end surface of the worm wheel 2 that contacts the ball bearing 6 of the large diameter portion 2a, and hatching is illustrated in FIG. Thus, an impact load is received at the root of the helical gear portion, and the root of the helical gear portion breaks relatively long as shown in FIG.

For this reason, when a member having a collapse load set so as to absorb impact force is provided in the connecting rod 7, the helical gear portion of the worm wheel 2 breaks relatively long, so that the helical gear portion is broken. As a result, the collapse load changes, and a new problem arises that a stable collapse load cannot be set.
Therefore, the present invention has been made paying attention to the unsolved problems of the above-described conventional example, and is an electric position adjustment type that can reliably prevent fluctuations in the collapse load due to the condition of the output side gear portion of the speed reducer. The object is to provide a steering device.

In order to achieve the above object, an electric position adjustment type steering apparatus according to claim 1 is an electric position adjustment type steering apparatus configured to be position-adjustable by an electric actuator, wherein the electric actuator is a rotation of an electric motor. A reduction gear that decelerates the force, and a linear motion mechanism that advances or retreats in the axial direction any one of a connecting rod formed with a male screw based on a reduction output of the reduction gear and a nut meshing with the connecting rod. The output side gear portion is formed of a synthetic resin material, and has a small diameter portion formed at each end in the axial direction and a large diameter portion formed between the small diameter portions, and each small diameter portion rotates via a bearing. The large-diameter portion is formed in a cylindrical shape to form a gear machining portion and a gear unmachined portion connected to the gear machining portion. The outer diameter of the large-diameter portion is that of the outer ring of the bearing. Than inside diameter Is fence set, said gear unprocessed portion side of the large diameter portion abuts the side surface of the inner ring of the bearing, the gear unprocessed portion is formed on the end side for receiving the impact load inputted from the steering wheel It is characterized by being.

Further, the electric position adjustable steering device according to claim 2, in the invention according to claim 1, before SL output gear unit, connecting part of the gear machining portion and the gear unprocessed portion is a gear rounded up shape It is characterized by being.

Furthermore, the electric position adjustable steering device according to claim 3 is the invention according to claim 1 or 2, wherein the speed reducer is constituted by a worm gear, is characterized in that the output-side gear unit is a worm wheel.

  According to the present invention, since the gear unmachined portion connected to the gear machining portion is formed at least at one end of the output side gear portion of the reduction gear, the gear unmachined portion abuts on the rolling bearing, thereby rolling. The contact area with the bearing is widened, and even when an impact load is transmitted, the effect of being able to reliably prevent the gear processed portion from being affected by breakage or the like without increasing the size of the output side gear portion can be obtained.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an overall configuration diagram showing a vehicle assembled with an electric telescopic adjustment type steering device according to the present invention, FIG. 2 is an overall configuration diagram showing a first embodiment of an electric telescopic adjustment type steering device according to the present invention, and FIG. 2 is a cross-sectional view taken along line AA in FIG. 2, FIG. 4 is a cross-sectional view taken along line BB in FIG. 3, FIG. 5 is a cross-sectional view of the main part of the present invention, and FIG. FIG. 7 is a view showing a worm wheel of a telescopic mechanism which is a main part of the present invention, and FIG. 8 is a cross-sectional view showing an electric motor mounting portion of the telescopic mechanism.

  In FIG. 1, a steering column device 10 includes a steering column 12 that supports a steering shaft 11 so as to be rotatable. A steering wheel 13 is mounted at the rear end of the steering shaft 11, and an intermediate shaft 15 is connected to the front end of the steering shaft 11 via a universal joint 14. A steering gear 17 composed of a rack and pinion mechanism or the like is connected to the intermediate shaft 15 through a universal joint 16 at the front end thereof. The output shaft of the steering gear 17 is connected to the steered wheel 19 through a tie rod 18.

When the driver steers the steering wheel 13, the rotational force is transmitted to the steering gear 17 via the steering shaft 11, the universal joint 14, the intermediate shaft 15, and the universal joint 16, and the rack and pinion mechanism rotates the vehicle. The steered wheels 19 are steered through the tie rods 18 after being converted into a linear motion in the width direction.
In addition, peripheral parts P such as a combination switch for driving a tilt mechanism 30 and a telescopic mechanism 50, which will be described later, and a column cover, are disposed at a rear portion of the steering column 12 in the vehicle.

As shown in FIG. 5, the steering column device 10 is inclined rearward and upward, and the steering shaft 11 has an outer shaft 11a to which a steering wheel 13 is attached, and an inner slidably engaged with the outer shaft 11a. It is comprised with the shaft 11b.
2 and 5, the steering column 12 includes an outer column 12a and an inner column 12b that is slidably held by the outer column 12a. The outer shaft 11a of the steering shaft 11 is rotatably supported by rolling bearings 12c disposed on the peripheral surface. The outer column 12a has a front end (left end in FIG. 2) on the side of the universal joint 14 supported on a lower bracket 22 attached to the vehicle body side member 21 so as to be swingable in the vertical direction by a pivot pin 23. An end (right end in FIG. 2) is supported by an upper bracket 24 attached to the vehicle body side member 21 so as to be movable in the vertical direction.

As shown in FIG. 3, the upper bracket 24 includes a mounting plate portion 24b having a bulging portion 24a with a central portion bulging upward attached to the vehicle body side member 21, and a bulging portion of the mounting plate portion 24b. The guide plate portions 24c and 24d extending downward from the left and right positions of 24a and the bottom plate portion 24e connecting the lower ends of the guide plate portions 24c and 24d are formed in a rectangular frame shape.
Then, the outer column 12a projects in the horizontal direction into the guide space 24f surrounded by the mounting plate portion 24b, the guide plate portions 24c and 24d and the bottom plate portion 24e of the upper bracket 24, and the end portions thereof are guided plate portions 24c and 24d. Guide plate portions 12d and 12e having vertical guide surfaces 12c that face each other are inserted.

  The guide plate portion 12e is held by the tilt mechanism 30 so as to be movable in the vertical direction. As shown in FIG. 3, the tilt mechanism 30 is rotatably supported in a substantially rectangular frame-shaped gear housing 31 integrally formed at the lower end portion of the guide plate portion 24d of the upper bracket 24, and the other. A screw shaft whose end is rotatably supported by a rolling bearing 34 disposed on the lower surface of the mounting plate portion 24b of the upper bracket 24 described above, extends vertically along the guide plate portion 24d, and is rotatably supported. 35.

A worm wheel 36 is attached to the screw shaft 35 at a position in the gear housing 31, and a worm 37 is engaged with the worm wheel 36.
As shown in FIGS. 3 and 6A, the worm wheel 36 includes small-diameter portions 36a and 36b formed at both upper and lower ends, and a large-diameter portion 36c formed at the center between the small-diameter portions 36a and 36b. And is formed in a cylindrical shape. The small diameter portions 36a and 36b are inserted into inner rings of ball bearings 38a and 38b fixed to the gear housing 31 and are rotatably held.

Further, as will be described later, when an impact load directed upward as viewed in FIG. 6A is transmitted to the large diameter portion 36c through the screw shaft 35, the side receiving the impact load, that is, the ball bearing 38a. A helical gear machining portion 36e is formed on the outer peripheral surface from the lower end side so as to form a cylindrical unmachined gear portion 36d on the side.
The worm 37 is engaged with the helical gear machining portion 36 e of the worm wheel 36, and the screw shaft 35 is engaged with the inner peripheral surface of the worm wheel 36.

As shown in FIG. 4, the worm 37 is rotatably held by rolling bearings 39a and 39b disposed in the gear housing 31, and one end thereof is formed on the guide plate portion 24d of the upper bracket 24. The output shaft 40a of the electric motor 40 fixed to the mounting plate portion 24g is connected via a coupling 39.
Here, the worm wheel 36 and the worm 37 constitute a reduction gear, and the worm wheel 36 is an output side gear portion. Further, the screw shaft 35 and the nut 45 constitute a linear motion mechanism.

  As shown in FIG. 3, a cylindrical cover 41 that covers the screw shaft 35 is disposed on the upper surface plate portion 31 b in which the insertion hole 31 a for inserting the screw shaft 35 of the gear housing 31 is formed. A lip 42 made of a synthetic resin such as polyurethane having a large elasticity that is in sliding contact with the outer peripheral surface of the screw shaft 35 is disposed at the tip (upper side in FIG. 3). Similarly, a lip 43 slidably contacting the outer peripheral surface of the screw shaft 35 is also provided on the lower end surface of the rolling bearing 34.

  A nut 45 held by a nut holder 44 having a square cross section is screwed between the lips 42 and 43 of the screw shaft 35. The nut holder 44 engages in a guide groove 46 formed in the guide plate portion 24d of the upper bracket 24 and extending in the vertical direction, so that the rotational movement around the axis of the screw shaft 35 of the nut holder 44 is restricted. The nut holder 44 is moved in the vertical direction by forward and reverse rotation of the screw shaft 35. An engaging pin 47 protruding from the nut holder 44 is engaged with a long hole 24h extending in the axial direction of the outer column 12a formed at the tip of the outer column 12a.

Therefore, when the worm 37 is driven forward / reversely by the electric motor 40, the screw shaft 35 is driven forward / reversely via the worm wheel 36, whereby the nut holder 44 is moved up and down, and the outer column 12a is centered on the pivot pin 23. As a result, the tilt function can be exerted.
A telescopic mechanism 50 as an electric actuator is provided between the outer column 12a and the inner column 12b of the steering column 12 as shown in FIG.

As shown in FIG. 5, the telescopic mechanism 50 includes a gear housing 51 fixed to the steering wheel 13 side of the outer column 12 a of the steering column 12. A worm wheel 54 is rotatably supported on the gear housing 51 by ball bearings 52 and 53 that are arranged to face each other at a predetermined distance in the axial direction of the steering column 12.
As shown in FIG. 7, the worm wheel 54 has a cylindrical shape having small diameter portions 54a and 54b formed at both left and right end portions and a large diameter portion 54c formed at the center between the small diameter portions 54a and 54b. Is formed. The small diameter portions 54a and 54b are inserted into the inner rings of ball bearings 52 and 53 fixed to the gear housing 51 and are rotatably held.

Further, as will be described later, when an impact load is transmitted from the right side as viewed in FIG. 6 to the large diameter portion 54c, a cylinder is formed on the side receiving the impact load, that is, on the ball bearing 53 side. A helical gear machining portion 54e is formed on the outer peripheral surface from the right end side so as to form a gear unmachined portion 54d.
As shown in FIGS. 7 and 8, the worm 56 connected to the output shaft of the electric motor 55 attached to the gear housing 51 is engaged with the helical gear machining portion 54 e of the worm wheel 54. The worm 56 constitutes a reduction gear, and the worm wheel 54 is an output side gear portion. The connecting rod 58 and the internal thread portion 54f on the inner periphery of the worm wheel 54 constitute a linear motion mechanism.

On the other hand, a connecting plate 57 extending in the same direction in the circumferential direction as the gear housing 51 is attached in the vicinity of the end of the inner column 12 b of the steering column 12 on the steering wheel 13 side. The connecting plate 57 is connected between the connecting plate 57 and the gear housing 51. A rod 58 is provided.
The connecting rod 58 includes an outer rod 58a having one end rotatably attached to the lower end of the connecting plate 57 by a pivot pin 59, and an inner rod 58b slidably engaged with the other end of the outer rod 58a. ing.

  In the engaging portion between the outer rod 58a and the inner rod 58b, the relative movement between the outer rod 58a and the inner rod 58b is restricted by a human force at a normal time, but an impact load is applied to the steering wheel 13, the inner rod 58 during a secondary collision. A connecting member 60 is provided that allows relative movement between the outer rod 58a and the inner rod 58b when transmitted to the outer rod 58a via the column 12b and the connecting plate 57.

The connecting member 60 has a structure in which a thin leaf spring material formed in a ring shape in which the cross section is uneven in the circumferential direction is formed in a ring shape, and a collapse load that allows relative movement of the outer rod 58a and the inner rod 58b is, for example, about It is set to 2 kN or more.
The inner rod 58b is formed with a male screw 58c on the side opposite to the outer rod 58a side. The male screw 58c is screwed into a female screw 54b of a worm wheel 54 rotatably supported by the gear housing 51, thereby connecting rod 58b. Is arranged so as to be parallel to the axial direction of the steering column 12.

  Therefore, by driving the electric motor 55 forward and backward, the worm wheel 54 can be driven forward and backward via the worm 56, and when the inner rod 58b moves forward and backward in the axial direction of the steering column 12, the outer rod 58a and The inner column 12b is driven to extend and contract in the axial direction via the connecting plate 57, so that a telescopic function can be exhibited.

Next, the operation of the first embodiment will be described.
Now, in order for the driver to adjust the tilt of the steering column 12 of the steering column device 10, the combination for the tilt mechanism provided in the peripheral part P provided in the vehicle rear portion of the steering column 12 shown in FIG. When the switch is operated in the tilt-up direction (or tilt-down direction), the electric motor 40 of the tilt mechanism 30 is driven forward (or reverse), for example. In response to this, by driving the screw shaft 35 in reverse (or forward) via the worm 37 and the worm wheel 36, the nut 45 moves upward (or downward) as viewed in FIG. Since the engaging pin 47 formed on 44 engages with the long hole 24h formed on the outer column 12a of the steering column 12, the outer column 12a rotates upward (or downward) around the pivot pin 23. Then, tilt-up (or tilt-down) adjustment can be performed.

  Then, when a horizontal impact load F acts on the steering wheel 13 to the front side of the vehicle as shown in FIG. 5 due to the secondary collision, the impact load F becomes a column axis direction component force Fx and a column axis perpendicular direction component force Fy. The steering wheel 13 is pushed upward by the component force Fy in the direction perpendicular to the column axis. For this reason, when the column axis perpendicular component Fy pushed up in the tilt-up direction is transmitted to the steering column 12, the column axis perpendicular component Fy is transmitted via the engagement pin 47 as shown in FIG. And is transmitted as an impact load that pushes upward from the nut holder 44 to the screw shaft 35.

  When the component force Fy in the direction perpendicular to the column axis is thus transmitted to the screw shaft 35, as shown in FIG. 6, the worm wheel 36 with which the screw shaft 35 is fitted is moved upward to the ball bearing 38a. Abut. At this time, since an unprocessed gear portion 36d is formed at the end of the worm wheel 36 on the ball bearing 38a side, the unprocessed gear portion 36d comes into contact with the inner ring of the ball bearing 38a. As in the example, the contact area is larger than when the helical gear machining portion 36e is in direct contact with the inner ring. For this reason, the surface pressure per unit area is reduced, and the deformation of the helical gear machining portion 36e is prevented, thereby reliably preventing the helical gear machining portion 36e from being deformed or damaged.

For this reason, even when the worm wheel 36 is formed of a synthetic resin material, it is possible to reliably prevent deformation and damage when an impact load is applied, and to prevent noise from occurring with the worm 37. be able to.
Further, in order for the driver to perform telescopic adjustment of the steering column of the steering column device 10, a combination switch for a telescopic mechanism provided on a peripheral part P disposed in the rear part of the steering column 12 shown in FIG. When operated in the extending direction (or contracting direction), the electric motor 55 of the telescopic mechanism 50 is driven forward (or reverse), for example.

  As a result, the worm wheel 54 is driven to rotate forward (or reversely) via the worm 56, whereby the inner rod 58 b of the connecting rod 58 moves to the steering wheel 13 side (or the side opposite to the steering wheel 13). The outer rod 59a moves to the steering wheel 13 side (or the side opposite to the steering wheel 13) via the member 60.

For this reason, the inner column 12b is pulled out from the outer column 12a via the connecting plate 57 (or the inner column 12b is inserted into the outer column 12a), and the steering column 12 is expanded (or contracted) to perform telescopic adjustment. be able to.
At this time, along with the movement of the inner column 12b, the outer shaft 11a of the steering shaft 11 moves relative to the inner shaft 11b.

  As described above, the telescopic mechanism 50 can extend and retract the steering column 12 to perform telescopic adjustment. However, when the connecting rod 58 is moved by the electric motor 55, the connecting member 60 includes the outer rod 58a and the inner rod. The expansion and contraction between 58b can be reliably prevented, and the outer rod 58a and the inner rod 58b can be integrated to move the connecting plate 57 in the vehicle longitudinal direction, and the inner column 12b can be moved in the vehicle longitudinal direction. However, when a column axial component force Fx is applied to the steering wheel 13 due to a secondary collision, the inner column 12b and the outer shaft 11a are first moved to the left as viewed in FIG. In response to this, the outer rod 58 a of the connecting rod 58 is moved to the left via the connecting plate 57, and the column axial component force Fx is transmitted to the connecting member 60. When the column axial component force Fx transmitted to the connecting member 60 reaches a set collapse load, slip occurs between the outer rod 58a and the inner rod 58b, and the inner rod 58b is inserted into the outer rod 58a. Thus, a predetermined collapse stroke can be secured.

Thus, when the impact load F that moves the vehicle forward is applied to the steering wheel 13, the column axial component force Fx is also transmitted to the worm wheel 54 via the connecting plate 57 and the connecting rod 58. .
As shown in FIG. 7B, the column axial component force Fx is received by the left end surface of the large-diameter portion 54 c coming into contact with the inner ring of the ball bearing 53 far from the steering wheel 13. However, since an unprocessed gear portion 54d that does not process a helical gear is formed at the end of the large-diameter portion 54c that contacts the inner ring of the ball bearing 53, the unprocessed gear portion 54d is shown in FIG. As shown in the hatching, the inner ring of the rolling bearing 53 comes into contact, and the contact area can be widened. Therefore, the surface pressure per unit area is lowered, and when an impact load is applied to the gear unmachined portion 54d. Deformation and damage can be reliably prevented.

For this reason, even when the worm wheel 54 is formed of a synthetic resin material, it is possible to reliably prevent deformation and damage when an impact load is applied, and to prevent noise from occurring with the worm 56. be able to.
As described above, since the worm wheel 54 is not deformed when the impact load is applied, when the impact load is applied to the connecting member 60 disposed between the outer rod 58a and the inner rod 58b of the connecting rod 58, When the impact load becomes equal to or greater than the collapse load set by the connecting member 60, relative movement occurs between the outer rod 58a and the inner rod 58b, so that the impact energy can be stably absorbed.

  Therefore, according to the first embodiment, since the gear unmachined portion 54d is formed at the end of the large diameter portion 54c of the worm wheel 54 that receives the impact load, the worm wheel 54 is rigid without increasing its size. When the impact load is applied, the helical gear machining portion 54e is damaged, and the collapse load of the connecting member 60 provided between the outer rod 58a and the inner rod 58b of the connecting rod 58 that is screwed into the worm wheel 54 varies. This can be reliably prevented and stable energy absorption can be performed.

Next, a second embodiment of the present invention will be described with reference to FIG. 9 showing a longitudinal sectional view of a worm wheel.
In the second embodiment, a rounded-up portion 54g extending toward the outer peripheral surface along the outer peripheral surface of the worm 56 is formed between the unmachined gear portion 54d and the helical gear processed portion 54e of the worm wheel 54 of the telescopic mechanism 50. Except for this, the configuration is the same as that of the first embodiment described above.

  Thus, according to the second embodiment, since the rounded-up portion 54g along the outer peripheral surface of the worm 56 is formed between the helical gear machining portion 54e and the gear non-machining portion 54d, the helical gear machining portion 54e and the gear The unprocessed portion 54d is gently connected, and the rigidity of the unprocessed portion 54d of the gear is further increased, so that the deformation and damage of the large-diameter portion 54c when an impact load is applied are ensured. Can be prevented. Moreover, by forming a rounded-up portion 54g between the helical gear machining portion 54e and the gear non-machining portion 54d, it can be produced from a cylindrical shape equal to the helical gear tip diameter by cutting with a hob, or produced by injection molding. It is possible to improve the workability.

In the second embodiment, the case where the rounded portion 54g is formed on the worm wheel 54 of the telescopic mechanism 50 has been described. However, the present invention is not limited to this, and the same applies to the worm wheel 36 of the tilt mechanism 30. Alternatively, a rounded-up portion may be formed between the helical gear processed portion 36e and the gear unprocessed portion 36d.
In the first and second embodiments, the unprocessed gear portion 54d is formed only at the end portions on the ball bearings 38a and 53 side that receive the impact load of the large diameter portions 36c and 54c in the worm wheels 36 and 54. Although the case has been described, the present invention is not limited to this, and unprocessed gear portions 36d and 54d are formed at both ends of the large-diameter portions 36c and 54c as shown in FIG. 10 showing a longitudinal sectional view of the worm wheel. In this case, there is an advantage that the worm wheel 54 can be mounted on the gear housings 31 and 51 without worrying about the mounting direction.

  In the first and second embodiments, the case where the outer column 12a of the steering column 12 is fixed to the vehicle body side member 21 has been described. However, the present invention is not limited to this, and the inner column 12b is connected to the lower bracket. 22 and the upper bracket 24 may be attached to the vehicle body side member 21, and the steering wheel 13 may be attached to the outer column 12a side.

  In the first embodiment, the case where the outer rod 58a of the connecting rod 58 is connected to the connecting plate 57 by the pivot pin 59 has been described. However, the present invention is not limited to this, and the connecting plate 57 of the connecting rod 58 is not limited thereto. A male screw is formed on the side end, the male screw is inserted into an insertion hole formed in the connecting plate and protruded from the opposite side, and a nut is screwed into the protruding portion and tightened, or the connecting plate 57 and the connecting rod 58 Can be formed into an arbitrary rigid coupling structure such as welding.

  Furthermore, in the said 1st Embodiment, although the case where the outer rod 58a and the inner rod 58b were connected with the connection member 60 formed in the ring shape of the waveform of a cross section in the circumferential direction was demonstrated, it is set as the said structure as the connection member 60. Any configuration such as press-fitting can be applied as long as the outer rod 58a and the inner rod 58b are moved relative to each other when an impact load greater than the set collapse load is transmitted.

Further, in the above embodiment, the case where the connecting member 60 that absorbs the impact load is formed on the connecting rod 58 has been described. However, the present invention is not limited to this, and the connecting member 60 of the connecting rod 58 is omitted. Instead of this, the gear housing 51 may be configured to be detached to the front side of the vehicle when an impact load is transmitted to the outer column 12a.
Further, in each of the above embodiments, the case where the present invention is applied only to the worm wheel 54 of the telescopic mechanism 50 has been described. However, the present invention is not limited to this, and the present invention is applied to the worm wheel 36 of the tilt mechanism 30. You may do it.

Further, in each of the above embodiments, the case where the speed reducer is a worm gear has been described. However, the present invention is not limited to this, and any gear such as a spur gear, a bevel gear, a helical gear, etc. is applied. The present invention can be applied to a reduced speed reducer.
Furthermore, in each of the above embodiments, the case where the worm wheel 54 is supported by the ball bearings 52 and 53 has been described. However, the present invention is not limited to this, and an arbitrary bearing such as a needle bearing or a sliding bearing is used. Can be applied.
Furthermore, in each of the above embodiments, the case where both the tilt mechanism 30 and the telescopic mechanism 50 are provided has been described. However, the present invention is not limited to this, and either the tilt mechanism 30 or the telescopic mechanism is omitted. You may do it.

1 is an overall configuration diagram illustrating a state in which a steering device according to the present invention is mounted on a vehicle. It is a side view except a steering wheel of a steering column device. It is sectional drawing on the AA line of FIG. It is sectional drawing on the BB line of FIG. It is a longitudinal cross-sectional view of the principal part of a steering column apparatus. It is a figure which shows the worm wheel of a tilt mechanism, Comprising: (a) is a longitudinal cross-sectional view, (b) is an end elevation showing a load receiving part. It is a figure which shows the worm wheel of a telescopic mechanism, Comprising: (a) is a longitudinal cross-sectional view, (b) is an end elevation showing a load receiving part. It is sectional drawing which shows the attachment part of the electric motor of a telescopic mechanism. It is a longitudinal cross-sectional view of the worm wheel which shows the 2nd Embodiment of this invention. It is a longitudinal cross-sectional view which shows the modification of a worm wheel. It is sectional drawing which shows the structural example in the case of forming a worm wheel with a synthetic resin material. FIGS. 11A and 11B are views showing the worm wheel in FIG. 11, in which FIG. 11A is an end view showing a load receiving portion, and FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Steering column apparatus, 11 ... Steering shaft, 11a ... Outer shaft, 11b ... Inner shaft, 12 ... Steering column, 12a ... Outer column, 12b ... Inter column, 13 ... Steering wheel, 14, 16 ... Universal joint, 15 ... Intermediate shaft, 17 ... steering gear, 18 ... tie rod, 19 ... steered wheel, 21 ... vehicle body side member, 22 ... lower bracket, 24 ... upper bracket, 30 ... tilt mechanism, 36 ... worm wheel, 36a, 36b ... small diameter part, 36c ... Large diameter part, 36d ... Gear unprocessed part, 36e ... Helical gear processed part, 50 ... Telescopic mechanism, 51 ... Gear housing, 52,53 ... Ball bearing, 54 ... Worm wheel, 54a, 54b ... Small diameter part, 54c ... Large diameter part, 54d ... Gear unprocessed part, 54e Helical gear processing unit, 54 g ... revaluation unit, 55 ... electric motor, 56 ... worm, 57 ... coupling plate, 58 ... linking rod, 58a ... outer rod, 58b ... inner rod

Claims (3)

An electric position adjustment type steering apparatus configured to be position adjustable by an electric actuator,
The electric actuator includes a speed reducer that reduces the rotational force of the electric motor, a connecting rod that forms a male screw based on a speed reduction output of the speed reducer, and a linear motion mechanism that advances or retracts in the axial direction a nut that meshes with the connecting rod. And
The output side gear portion of the speed reducer is formed of a synthetic resin material, and has a small diameter portion formed at both ends in the axial direction, and a large diameter portion formed between the small diameter portions,
Each of the small diameter portions is rotatably supported via a bearing, and the large diameter portion is formed in a cylindrical shape to form a gear machining portion and a gear non-machining portion connected to the gear machining portion,
The outer diameter of the large diameter portion is set smaller than the inner diameter of the outer ring of the bearing, the gear unmachined portion side of the large diameter portion is in contact with the side surface of the inner ring of the bearing ,
The non-gear processed portion is formed on an end portion side that receives an impact load input from a steering wheel . The electric position adjusting type steering apparatus according to claim 1, wherein the output side gear portion has a gear rounding shape at a connecting portion between the gear machining portion and the gear non-machining portion . The reduction gear is constituted by a worm gear, an electric position adjustable steering device according to claim 1 or 2 output-side gear unit is characterized Oh Rukoto with the worm wheel.

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